This invention relates to improvements in the design of piping flanges and relates to the use of stress analysis to assist in the design of optimum configurations for a flange coupler as described in my prior patent, U.S. Pat. No. 5,413,389 issued May 9, 1995 and entitled, "Cast Convoluted Piping Flange". In the referenced patent a piping flange was described having a convoluted design with a transition in thickness from an outer rim to an inner rim of the flange. The convoluted design provided the rigidity or stiffness necessary to insure a uniform coupling face for uniform deformation of a gasket or seal, while minimizing the weight of the flange by eliminating unnecessary material.
The convoluted flanges and flange couplers of the type described in the reference patent are successful in accomplishing the objectives enumerated. Furthermore, the technique of computer aided stress analysis in the design of piping flanges has led to further improvements in the configuration of flanges that address the issue of stresses transmitted to the pipe, and in the design and construction of composite material flanges.
With regard to the latter, my prior patent, U.S. Pat. No. 4,458,924 issued Jul. 10, 1984, entitled, "Bimetal Flange Connector", describes a bimetal flange that utilizes a hub of a first metal bonded to a rim of a second metal. The concept of a composite flange of two materials and the use of a recess to reduce weight and optimize stress distribution is described in the referenced bimetal flange patent.
The subject invention includes certain of the features of the devices in the referenced patents. The advantage of computer aided stress analysis provides embodiments of piping flanges that fully consider the effect of the flange configuration in transmitting stresses to the pipe as well as efficiently distributing stresses in the flange itself.